Premature rev limit at 6500rpm?

[indyfto]

My mivec has recently ceased to work causing a revlimit in all gears of approx 6500rpm. It is a 96 gpx tip and I am unsure what the most likely problem is.

I have checked the oil, checked for loose sensors all ok. Reset the ecu but still no mivec. The car runs perfect below 6500rpm and there are no warning lights up on the dash. Is there any point in getting an MUT check done as if there was a sensor problem wouldn't a light on the dash indicate something of that sort is wrong? Or have I cleared any codes by resetting the ecu (if there were any in the first place as there wasn't any warning lights either?)

The car is at the mechanics today and they think it could be a coil pack or spark plug problem but they can't be sure. Is this likely given the car was running fine before and still runs fine now (albeit below 6500rpm)? The car has 85000kms and I assume the plugs and coils are from new so getting oldish...Don't wanna fork out for all this stuff if its not too likely to be the problem. Although I know the plugs need changing very soon anyway.

Any help woud be most appreciated.

[MADFTO]

6500rpm is the cold engine rev limiter.
Mivec will not engage while the engine is in this mode

I'm not sure which temperature sensor trips the car into normal operation mode. Could someone reply this with the answer?

I remember a post about this in a past, might be prudent to do a search =)

[G_A_V]

Its most likely a sensor, the ecu also sets a rev limit of 6500 when ever one of the sensors are not reading anything, from personal experiance if its a non-mivec and they car is not stalling it is most likely any of the sensors on the air intake (when ever they are not working the car revs up and down till it stalls)
Also have a look down the left hand side of the motor near the belts, i have seen where some of these have fraied and cut wires going to the sensors, your proberbly best finding somewhere with a mut II though to find out exactly what sensors not working